Last updated: February 24, 2025
In September, San Clemente experiences a delightful blend of warmth and mildness, with peak temperatures soaring to a maximum of 40°C (105°F) while averaging around a comfortable 23°C (73°F). The nights offer a refreshing contrast, with temperatures dipping to a minimum of 13°C (56°F). This month sees minimal precipitation, with only 3 mm (0.1 in) of rain recorded across just 1 day, making it an ideal time to enjoy outdoor activities. The air carries a humidity level of 68%, contributing to the coastal charm that defines San Clemente's late summer ambiance.
In September, San Clemente experiences a transition into the fall season, yet the warmth of summer lingers. With a minimum temperature of 13°C (56°F) and an average of 23°C (73°F), the days remain pleasantly warm, perfect for beach activities or outdoor adventures. However, temperatures can reach a sizzling maximum of 40°C (105°F), making it one of the hottest months of the year. This trend reflects a consistent rise from the cooler months of spring, with September showcasing a comfortable blend of warmth that invites visitors to soak in the last rays of summer before the cooler autumn temperatures arrive. The month stands out not just for its heat but for the vibrant atmosphere it creates, drawing both locals and travelers to its sun-kissed shores.
In September, San Clemente experiences a transition into fall with minimal rainfall, recording just 3 mm (0.1 in) over a single day. This trend of low precipitation reflects the dry summer months that precede it, where July and August also saw negligible amounts of rain. As the year progresses into the later months, a gradual increase in precipitation can be observed in October and November, suggesting that the region begins to shift toward its wetter season. The overall pattern indicates a pronounced dry spell during the summer, with September holding steady as the tail end of this trend before the anticipated autumn rains set in.
As summer fades into autumn, September in San Clemente experiences a gentle decline in humidity, dropping to 68%. This marks the continuation of a trend seen throughout the late summer months, where humidity gradually decreases from a peak of 79% in February down to the more comfortable levels of September and October. With August closing at 69%, September allows residents and visitors to enjoy pleasant coastal breezes, making it an ideal time for outdoor activities. The shift to lower humidity not only enhances comfort but also signifies the transition toward a drier climate as the year winds down, setting the stage for a crisp and refreshing fall.
In September, San Clemente experiences a UV Index of 10, maintaining a very high exposure category that demands attention. This mirrors the trend established over the summer months, where the UV Index reached its peak at 11 from May through August. As temperatures begin to cool, the UV level slightly decreases from the summer highs, yet sun safety remains crucial, with a burn time of just 15 minutes. Residents and visitors alike should be vigilant, employing protective measures to shield their skin from harmful rays. For further insights and details, explore the San Clemente UV Index.
UV Risk Categories
As summer gracefully transitions into autumn, September in San Clemente continues to bask in the glow of sunny days, boasting an impressive 317 hours of sunshine. This marks a subtle decline from the peak of summer, where July dazzles with 379 hours of radiant warmth. Even as the days grow shorter, the sunshine in September remains abundant, outshining earlier months like February and March, which saw 237 and 290 hours respectively. The consistent sunlit embrace of San Clemente not only invites outdoor adventures but also heralds the onset of a serene coastal charm, making it a delightful time for locals and visitors alike to savor the gentle shift from summer to fall.
As summer transitions into fall, September in San Clemente boasts the highest likelihood of sunny weather at an impressive 71%. This marks a notable uptick from the previous months, where the chances hovered between 51% and 70%. While the summer months of July and August are popular for beachgoers, September continues to shine, often bringing warm days and clear skies. With the weather still holding onto the summer warmth, it’s an ideal time for outdoor activities before the cooler fall temperatures set in. As daylight shortens and the seasons shift, San Clemente's sunny disposition in September captivates both locals and visitors alike.
As summer transitions into fall, September in San Clemente witnesses a balanced daylight duration of 12 hours. Following the long, sun-drenched days of July and June, which each offer 14 hours of daylight, the gradual decrease becomes apparent. August sees a slight dip to 13 hours, and by September, we're welcomed by just an hour less. This subtle shift not only marks the onset of the autumn season but also hints at the forthcoming shorter days, as October brings 11 hours of daylight. These trends reflect the natural rhythm of the year, with sunlight gradually receding, paving the way for the cozy, shorter days of winter.
As September breezes in, the winds of San Clemente settle into a gentle rhythm, averaging 1.7 m/s (4 mph). This marks a continuation of the trend established in August, where cooler summer days yield to the serene calm of early fall. Throughout the year, the wind speeds have shown subtle fluctuations, peaking at 2.2 m/s (5 mph) from March to May, while the late summer and early autumn months reveal calmer conditions. As autumn approaches, these softer winds create an ideal backdrop for outdoor activities, offering a pleasant reminder of the coastal charm that defines this beautiful Californian town. The gradual dip in wind speed during this period signals not only a transition in seasons but also invites locals and visitors alike to embrace the laid-back lifestyle of San Clemente.
The weather in San Clemente changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in San Clemente and find detailed weather information for every month.
In September, temperatures in San Clemente are quite warm, with an average high of 40°C (105°F) and minimal precipitation of just 3 mm over a single day, creating a dry atmosphere with 68% humidity. In contrast, January brings significantly cooler weather, with an average high of 30°C (87°F) and much higher precipitation levels at 71 mm over five days, resulting in a more humid environment at 74%. For a detailed look at January's conditions, you can visit San Clemente weather in January.
September typically enjoys warmer weather, with average temperatures ranging from a minimum of 13°C (56°F) to a maximum of 40°C (105°F). The month is relatively dry, with only 3 mm of precipitation over about 1 day, and the humidity hovers around 68%. In contrast, February presents a cooler climate, with temperatures ranging from a chilly minimum of 3°C (38°F) to a pleasant maximum of 29°C (85°F). This month experiences significantly more rainfall, totaling 66 mm over 6 days, and the humidity increases slightly to 79%. For more detailed information, you can visit San Clemente weather in February.
September typically offers warmer weather than March, with average temperatures reaching around 23°C (73°F), while March sees a cooler average of 14°C (58°F). The hottest days in September can soar up to 40°C (105°F), compared to March's maximum of 28°C (82°F). Additionally, September experiences minimal rainfall with only 3 mm (0.1 in) across just 1 day, while March is significantly wetter, averaging 68 mm (2.7 in) over 10 days. Humidity levels are relatively comparable, with September at 68% and March slightly higher at 75%. For more detailed insights, you can check San Clemente weather in March.
In comparing the weather of September and April, September tends to be warmer, with average temperatures around 23°C (73°F) and maximums soaring as high as 40°C (105°F). Conversely, April's temperatures are cooler, averaging 16°C (62°F) and peaking at 34°C (94°F). While both months exhibit similar humidity levels, with September at 68% and April slightly higher at 70%, April experiences significantly more rainfall, totaling 30 mm (1.2 in) over an average of 3 days compared to September's minimal precipitation of just 3 mm (0.1 in) on one day. For more insights, you can check San Clemente weather in April.
In September, the weather typically warms up, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 40°C (105°F), resulting in a hot average of 23°C (73°F). The month experiences very little precipitation, with only 3 mm (0.1 in) falling over just one day, and humidity levels at 68%. In contrast, May offers a cooler climate, with temperatures varying from a low of 9°C (49°F) to a high of 31°C (87°F), averaging at 17°C (63°F). May sees more rain, accumulating 18 mm (0.7 in) over three days, and a slightly higher humidity of 70%. For more detailed information, check out San Clemente weather in May.
In September, temperatures can reach a sweltering maximum of 40°C (105°F), with an average of 23°C (73°F) and a minimum of 13°C (56°F), making it significantly hotter than June. In contrast, June sees a milder maximum of 33°C (92°F), with an average temperature of 20°C (68°F) and a minimum of 12°C (54°F). Both months experience low precipitation, with September receiving just 3 mm (0.1 in) over 1 day and June registering only 2 mm (0.1 in) with no rainy days at all. Although humidity remains relatively high in both months, it is slightly lower in June at 72%, compared to September's 68%. For more specific weather details, you can check San Clemente weather in June.
In comparison to July, September experiences slightly milder temperatures, with a minimum of 13°C (56°F) compared to July's minimum of 15°C (60°F). Both months boast similar average temperatures of around 23°C (73°F), but July can reach a slightly higher maximum at 41°C (106°F) compared to September's 40°C (105°F). Rainfall remains minimal in both months, with September receiving precipitation on one day, whereas July sees no recorded rain. Humidity levels are also quite comparable, with September at 68% and July at 73%. For more detailed information on July’s weather, you can check San Clemente weather in July.
In comparing the weather patterns of September and August, September presents a slightly cooler climate overall, with average temperatures ranging from a minimum of 13°C (56°F) to a maximum of 40°C (105°F), while August boasts a higher average, with temperatures ranging from 16°C (62°F) at night to a daytime maximum of 35°C (95°F). Both months experience minimal precipitation, with September receiving rain on one day and August remaining completely dry, as noted in San Clemente weather in August. Humidity levels remain similar, with September at 68% and August slightly higher at 69%, suggesting both months are relatively humid but still comfortable.
In comparing the weather of September and October, September is characterized by higher average temperatures, ranging from a minimum of 13°C (56°F) to a maximum of 40°C (105°F), while October sees a slight drop with temperatures ranging from a minimum of 9°C (49°F) to a maximum of 38°C (101°F). Additionally, September experiences very little precipitation, only 3 mm (0.1 in) over just one day, compared to October, which records 11 mm (0.4 in) across two days. Humidity remains relatively stable, with September at 68% and October slightly lower at 67%. For more detailed information, you can refer to San Clemente weather in October.
In comparing the weather between September and November, September typically experiences warmer temperatures, with an average of 23°C (73°F) and a maximum reaching up to 40°C (105°F). In contrast, November brings cooler conditions, with an average temperature of 17°C (63°F) and a maximum of 33°C (91°F). Additionally, September is relatively dry, receiving only 3 mm (0.1 in) of precipitation over just one day, whereas November sees a notable increase in rainfall, accumulating 26 mm (1.0 in) over two days. Both months share a consistent humidity level of 68%, providing a humid atmosphere year-round. For more specifics on November's weather, you can check San Clemente weather in November.
In September, the weather is considerably warmer, with temperatures ranging from a pleasant 13°C (56°F) at night to a sweltering 40°C (105°F) during the day. The month is relatively dry, with only 3 mm (0.1 in) of precipitation and humidity hovering around 68%. In contrast, December brings cooler temperatures, averaging a mild 13°C (56°F), with nighttime lows dropping to 4°C (39°F) and daily highs reaching 27°C (81°F). This month experiences significantly more rainfall, totaling 73 mm (2.9 in) across approximately five days, while humidity slightly increases to 71%. For more details on December temperatures and conditions, you can refer to San Clemente weather in December.
As summer transitions to fall, September in San Clemente presents a unique climate experience. While temperatures can peak at a sizzling 40°C, the overall feel is comfortably warm with averages resting around 23°C. Unlike the wetter months, precipitation remains scarce, with merely one day of rain, making this a remarkably dry period. The air carries a moderate humidity of 68%, providing a pleasant atmosphere that's ideal for outdoor activities. This distinct blend of warmth and minimal rain sets September apart from the cooler, wetter months that follow. For a more detailed understanding of the weather trends, check out the San Clemente Climate.